Simple blockchain with Python

blockchain.py

This file contains the implementation of the Blockchain class and the Transaction class. The Blockchain class implements a basic blockchain data structure to store transactions in a chain of blocks. The Transaction class implements the functionality to create a transaction and sign the transaction using a private key.

It contains the following classes:

• Block: A class that represents a single block in the blockchain. It contains a block number, a list of transactions, a nonce (a random number used to create a unique hash), and the hash of the previous block.

• Blockchain: A class that represents a full blockchain. It contains a list of blocks and has functions for adding new blocks and validating the chain.

blockchain_server.py

This file implements a RESTful API for interacting with the blockchain. It uses the Flask framework to create endpoints for adding transactions and blocks to the chain.

It has the following routes:

• /transactions: A POST endpoint for adding transactions to the blockchain. It expects a JSON payload with the following keys: sender_blockchain_address, recipient_blockchain_address, sender_public_key, value, and signature.
• /mine: A GET endpoint for mining new blocks. This involves adding a block to the chain that contains all unconfirmed transactions and a nonce that results in a unique hash.
• /chain: A GET endpoint for retrieving the entire blockchain.

wallet.py

This file implements a simple wallet for cryptocurrency transactions.

It contains the following classes:

• Wallet: A class that represents a wallet and contains a private key, a public key, and a blockchain address.
• Transaction: A class that represents a transaction between wallets. It contains the sender's private key, public key, and blockchain address, the recipient's blockchain address, and the value being transferred. It also generates a signature using the sender's private key.

wallet_server.py

This file implements a RESTful API for interacting with the wallet. It uses the Flask framework to create endpoints for creating new wallets and transactions.

It has the following routes:

• /wallet: A POST endpoint for creating a new wallet. It returns a JSON payload with the following keys: private_key, public_key, and blockchain_address.
• /transaction: A POST endpoint for creating a new transaction. It expects a JSON payload with the following keys: sender_private_key, sender_blockchain_address, recipient_blockchain_address, sender_public_key, and value.
• /wallet/amount: A GET endpoint for retrieving the amount of cryptocurrency associated with a wallet's blockchain address. It expects a query parameter of blockchain_address.

Usage

1. Clone the repository
2. Run the blockchain server using python blockchain_server.py
3. Run the wallet server using python wallet_server.py
4. Interact with the servers using API requests.